The present invention is directed to an arrangement, a positioning and an energy supply system for self-contained mobile robots.
In order for a mobile robot to be completely autonomous, it is necessary for the robot to be supplied by an energy source without any external intervention.
A solution to this problem, only available if the robot is operative outdoors, is to use the ambient light which is converted into electricity by means of photovoltaic cells located on the illuminated surface of the device. The electricity so produced may be used immediately or may be stored in a rechargeable battery. This will free the robot from the energy supply constraint.
The photovoltaic cell system will limit the use of the robot to operations requiring a low power consumption and to a use in the open air which will make it dependent on the sunshine conditions. Other solutions have been contemplated in the context of the automatic re-filling of fuel reservoirs for internal combustion engine devices. The automatic connection to an electric network for the recharge of a battery of a device with an electric motor has also been contemplated.
These solutions require a precise positioning of the robot and a physical connection to the recharging or refuelling system.
The localisation by the robot of the point of re-supplying requires also a relatively complicated guiding system, for example by means of electric wires.
U.S. Pat. No. 4,777,416 discloses an autonomous mobile robot able to automatically join a resupplying station when the level of a rechargeable battery drops below a predetermined value. The positioning of such robot is however determined at all times and the motion in direction of the recharge station is effected according to a predetermined path. Such a system is complicated and requires frequent positioning calibrations. Moreover, in this document, a physical connection is required for the recharging operation, more particularly by means of a retractable arm.
The object of the invention is to overcome these difficulties and disadvantages.
According to the invention, a mobile self-contained robot is provided, able to re-supply itself with energy without having to physically be connected to a re-supplying source, without a precise positioning and with the use of the source itself as part of a positioning and guiding system for the resupplying in energy.
In normal operation, the robot moves in its working zone whose limits, for example determined by obstacles or a metallic wire, are detected in a known manner by appropriated sensors located on or in the robot.